[PATCH 15/18] nvmet-tcp: enable TLS handshake upcall

Hannes Reinecke
2023-03-29T14:00:02Z

Add functions to start the TLS handshake upcall when
the TCP RSAS sectype is set to 'tls1.3'.

Signed-off-by: Hannes Reincke <hare@suse.de>
---
drivers/nvme/target/configfs.c | 32 +++++++-
drivers/nvme/target/tcp.c | 135 ++++++++++++++++++++++++++++++++-
2 files changed, 163 insertions(+), 4 deletions(-)

diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
index ca66ee6dc153..36fbf6a22d09 100644
--- a/drivers/nvme/target/configfs.c
+++ b/drivers/nvme/target/configfs.c
@@ -159,10 +159,12 @@ static const struct nvmet_type_name_map nvmet_addr_treq[] = {
{ NVMF_TREQ_NOT_REQUIRED, "not required" },
};

+#define NVMET_PORT_TREQ(port) ((port)->disc_addr.treq & NVME_TREQ_SECURE_CHANNEL_MASK)
+
static ssize_t nvmet_addr_treq_show(struct config_item *item, char *page)
{
- u8 treq = to_nvmet_port(item)->disc_addr.treq &
- NVME_TREQ_SECURE_CHANNEL_MASK;
+ struct nvmet_port *port = to_nvmet_port(item);
+ u8 treq = NVMET_PORT_TREQ(port);
int i;

for (i = 0; i < ARRAY_SIZE(nvmet_addr_treq); i++) {
@@ -193,6 +195,17 @@ static ssize_t nvmet_addr_treq_store(struct config_item *item,
return -EINVAL;

found:
+#ifdef CONFIG_NVME_TLS
+ if (port->disc_addr.trtype == NVMF_TRTYPE_TCP) {
+ if (port->disc_addr.tsas.tcp.sectype != NVMF_TCP_SECTYPE_TLS13) {
+ pr_warn("cannot change TREQ when TLS is not enabled\n");
+ return -EINVAL;
+ } else if (nvmet_addr_treq[i].type == NVMF_TREQ_NOT_SPECIFIED) {
+ pr_warn("cannot set TREQ to 'not specified' when TLS is enabled\n");
+ return -EINVAL;
+ }
+ }
+#endif
treq |= nvmet_addr_treq[i].type;
port->disc_addr.treq = treq;
return count;
@@ -373,6 +386,7 @@ static ssize_t nvmet_addr_tsas_store(struct config_item *item,
const char *page, size_t count)
{
struct nvmet_port *port = to_nvmet_port(item);
+ u8 treq = port->disc_addr.treq & ~NVME_TREQ_SECURE_CHANNEL_MASK;
int i;

if (nvmet_is_port_enabled(port, __func__))
@@ -391,6 +405,20 @@ static ssize_t nvmet_addr_tsas_store(struct config_item *item,

found:
nvmet_port_init_tsas_tcp(port, nvmet_addr_tsas_tcp[i].type);
+ if (nvmet_addr_tsas_tcp[i].type == NVMF_TCP_SECTYPE_TLS13) {
+#ifdef CONFIG_NVME_TLS
+ if (NVMET_PORT_TREQ(port) == NVMF_TREQ_NOT_SPECIFIED)
+ treq |= NVMF_TREQ_REQUIRED;
+ else
+ treq |= NVMET_PORT_TREQ(port);
+#else
+ pr_err("TLS not supported\n");
+ return -EINVAL;
+#endif
+ } else {
+ /* Set to 'not specified' if TLS is not enabled */
+ treq |= NVMF_TREQ_NOT_SPECIFIED;
+ }
return count;
}

diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
index 5931971d715f..ebec882120fd 100644
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -11,6 +11,10 @@
#include <linux/nvme-tcp.h>
#include <net/sock.h>
#include <net/tcp.h>
+#ifdef CONFIG_NVME_TLS
+#include <net/handshake.h>
+#include <linux/nvme-keyring.h>
+#endif
#include <linux/inet.h>
#include <linux/llist.h>
#include <crypto/hash.h>
@@ -40,6 +44,16 @@ module_param(idle_poll_period_usecs, int, 0644);
MODULE_PARM_DESC(idle_poll_period_usecs,
"nvmet tcp io_work poll till idle time period in usecs");

+#ifdef CONFIG_NVME_TLS
+/*
+ * TLS handshake timeout
+ */
+static int tls_handshake_timeout = 30;
+module_param(tls_handshake_timeout, int, 0644);
+MODULE_PARM_DESC(tls_handshake_timeout,
+ "nvme TLS handshake timeout in seconds (default 30)");
+#endif
+
#define NVMET_TCP_RECV_BUDGET 8
#define NVMET_TCP_SEND_BUDGET 8
#define NVMET_TCP_IO_WORK_BUDGET 64
@@ -130,6 +144,10 @@ struct nvmet_tcp_queue {
bool data_digest;
struct ahash_request *snd_hash;
struct ahash_request *rcv_hash;
+#ifdef CONFIG_NVME_TLS
+ struct key *tls_psk;
+ struct delayed_work tls_handshake_work;
+#endif

unsigned long poll_end;

@@ -1474,6 +1492,10 @@ static void nvmet_tcp_release_queue_work(struct work_struct *w)
nvmet_tcp_free_cmds(queue);
if (queue->hdr_digest || queue->data_digest)
nvmet_tcp_free_crypto(queue);
+#ifdef CONFIG_NVME_TLS
+ if (queue->tls_psk)
+ key_put(queue->tls_psk);
+#endif
ida_free(&nvmet_tcp_queue_ida, queue->idx);
page = virt_to_head_page(queue->pf_cache.va);
__page_frag_cache_drain(page, queue->pf_cache.pagecnt_bias);
@@ -1488,8 +1510,12 @@ static void nvmet_tcp_data_ready(struct sock *sk)

read_lock_bh(&sk->sk_callback_lock);
queue = sk->sk_user_data;
- if (likely(queue))
- queue_work_on(queue_cpu(queue), nvmet_tcp_wq, &queue->io_work);
+ if (queue->data_ready)
+ queue->data_ready(sk);
+ if (likely(queue) &&
+ queue->state != NVMET_TCP_Q_TLS_HANDSHAKE)
+ queue_work_on(queue_cpu(queue), nvmet_tcp_wq,
+ &queue->io_work);
read_unlock_bh(&sk->sk_callback_lock);
}

@@ -1597,6 +1623,89 @@ static int nvmet_tcp_set_queue_sock(struct nvmet_tcp_queue *queue)
return ret;
}

+#ifdef CONFIG_NVME_TLS
+static void nvmet_tcp_tls_queue_restart(struct nvmet_tcp_queue *queue)
+{
+ spin_lock(&queue->state_lock);
+ if (queue->state != NVMET_TCP_Q_TLS_HANDSHAKE) {
+ pr_warn("queue %d: TLS handshake already completed\n",
+ queue->idx);
+ spin_unlock(&queue->state_lock);
+ return;
+ }
+ queue->state = NVMET_TCP_Q_CONNECTING;
+ spin_unlock(&queue->state_lock);
+
+ pr_debug("queue %d: restarting queue after TLS handshake\n",
+ queue->idx);
+ /*
+ * Set callbacks after handshake; TLS implementation
+ * might have changed the socket callbacks.
+ */
+ nvmet_tcp_set_queue_sock(queue);
+}
+
+static void nvmet_tcp_tls_handshake_done(void *data, int status,
+ key_serial_t peerid)
+{
+ struct nvmet_tcp_queue *queue = data;
+
+ pr_debug("queue %d: TLS handshake done, key %x, status %d\n",
+ queue->idx, peerid, status);
+ if (!status) {
+ spin_lock(&queue->state_lock);
+ queue->tls_psk = key_lookup(peerid);
+ if (IS_ERR(queue->tls_psk)) {
+ pr_warn("queue %d: TLS key %x not found\n",
+ queue->idx, peerid);
+ queue->tls_psk = NULL;
+ }
+ spin_unlock(&queue->state_lock);
+ }
+ cancel_delayed_work_sync(&queue->tls_handshake_work);
+ if (status)
+ nvmet_tcp_schedule_release_queue(queue);
+ else
+ nvmet_tcp_tls_queue_restart(queue);
+}
+
+static void nvmet_tcp_tls_handshake_timeout_work(struct work_struct *w)
+{
+ struct nvmet_tcp_queue *queue = container_of(to_delayed_work(w),
+ struct nvmet_tcp_queue, tls_handshake_work);
+
+ pr_debug("queue %d: TLS handshake timeout\n", queue->idx);
+ nvmet_tcp_schedule_release_queue(queue);
+}
+
+static int nvmet_tcp_tls_handshake(struct nvmet_tcp_queue *queue)
+{
+ int ret = -EOPNOTSUPP;
+ struct tls_handshake_args args;
+
+ if (queue->state != NVMET_TCP_Q_TLS_HANDSHAKE) {
+ pr_warn("cannot start TLS in state %d\n", queue->state);
+ return -EINVAL;
+ }
+
+ pr_debug("queue %d: TLS ServerHello\n", queue->idx);
+ args.ta_sock = queue->sock;
+ args.ta_done = nvmet_tcp_tls_handshake_done;
+ args.ta_data = queue;
+ args.ta_keyring = nvme_keyring_id();
+ args.ta_timeout_ms = tls_handshake_timeout * 2 * 1024;
+
+ ret = tls_server_hello_psk(&args, GFP_KERNEL);
+ if (ret) {
+ pr_err("failed to start TLS, err=%d\n", ret);
+ } else {
+ queue_delayed_work(nvmet_wq, &queue->tls_handshake_work,
+ tls_handshake_timeout * HZ);
+ }
+ return ret;
+}
+#endif
+
static void nvmet_tcp_alloc_queue(struct nvmet_tcp_port *port,
struct socket *newsock)
{
@@ -1609,6 +1718,10 @@ static void nvmet_tcp_alloc_queue(struct nvmet_tcp_port *port,

INIT_WORK(&queue->release_work, nvmet_tcp_release_queue_work);
INIT_WORK(&queue->io_work, nvmet_tcp_io_work);
+#ifdef CONFIG_NVME_TLS
+ INIT_DELAYED_WORK(&queue->tls_handshake_work,
+ nvmet_tcp_tls_handshake_timeout_work);
+#endif
queue->sock = newsock;
queue->port = port;
queue->nr_cmds = 0;
@@ -1622,6 +1735,7 @@ static void nvmet_tcp_alloc_queue(struct nvmet_tcp_port *port,
init_llist_head(&queue->resp_list);
INIT_LIST_HEAD(&queue->resp_send_list);

+#ifdef CONFIG_NVME_TLS
if (queue->state == NVMET_TCP_Q_TLS_HANDSHAKE) {
queue->sock_file = sock_alloc_file(queue->sock, O_CLOEXEC, NULL);
if (IS_ERR(queue->sock_file)) {
@@ -1630,6 +1744,7 @@ static void nvmet_tcp_alloc_queue(struct nvmet_tcp_port *port,
goto out_free_queue;
}
}
+#endif

queue->idx = ida_alloc(&nvmet_tcp_queue_ida, GFP_KERNEL);
if (queue->idx < 0) {
@@ -1651,6 +1766,22 @@ static void nvmet_tcp_alloc_queue(struct nvmet_tcp_port *port,
list_add_tail(&queue->queue_list, &nvmet_tcp_queue_list);
mutex_unlock(&nvmet_tcp_queue_mutex);

+#ifdef CONFIG_NVME_TLS
+ if (queue->state == NVMET_TCP_Q_TLS_HANDSHAKE) {
+ struct sock *sk = queue->sock->sk;
+
+ /* Restore the default callbacks before starting upcall */
+ read_lock_bh(&sk->sk_callback_lock);
+ sk->sk_user_data = NULL;
+ sk->sk_data_ready = port->data_ready;
+ read_unlock_bh(&sk->sk_callback_lock);
+ if (!nvmet_tcp_tls_handshake(queue))
+ return;
+
+ /* TLS handshake failed, terminate the connection */
+ goto out_destroy_sq;
+ }
+#endif
ret = nvmet_tcp_set_queue_sock(queue);
if (ret)
goto out_destroy_sq;
--
2.35.3